• Neil Yeager
    What do you guys do fo pre-grinding prior to heat treat. I only work with carbon steels, and have been doing some pre grinds for the bevels, but I am really thinking that I will eliminate that step and wait till after HT.
  • Jeff Kushen
    Hey Neil,

    As with anything, 'it depends'.

    For me the answer is even for carbon steel, if it is very thin ,like a Chefs knife or EDC (I tend to do anything 3/32" or less) I grid POST HEAT TREAT. Its not that much more difficult with sharp belts, and it lessens the chances of warping.

    For normal stainless steels (12c27, AEB-L, ant the like) I grind all post heat treat. For thicker carbon and super steels, I grind pre-heat treat. I can't imagine the amount of effort and belts used to grind a CPMS35V or some 'super-steels' after heat treat...

    Ultimately, it depends on YOUR grinding style! If you are heavy-handed, grind after. if you use light passes and dip often you may be able to get away with doing it before.

    And always normalize / thermal cycle before heat treating. I bought a couple 1" thick aluminum plates, that I put into my bench vise, and if I am worried or have a feeling about it warping, i clamp it in the plates when I pull it out from thermal cycling.

  • Rix Raven
    I tried both ways and I find that (like Jeff) it lessens potential warp if I grind after HT. Specially if its layered. And with a fresh coarse grit it will not take long to take off the excess weight.
  • JR Knifemaker
    If it’s a shorter knife, say a hunter/bushcraft then I’ll always lay the foundations before heat treat, as long as I’m leaving 1-2mm at the edge (not sure what that is in imperial, but about the width of an ant!!)
  • Finn Leslie
    I usually do a fair chunk of the grinding beforehand. Saves time since I don’t constantly have to dunk the blade to keep it cool and the belts grind MUCH faster on annealed steel. Thinner stock I do less grinding beforehand to cut down on warping but thinner knives are usually quite a bit easier to correct warps anyways.
  • Neil Yeager
    Ha, but we got some Big A.... ants here in Thailand.
  • Neil Yeager
    Thanks for all the comments. I am going to try a small batch w/o pre grind and see.
  • JR Knifemaker
    go by the nice small British ant!
  • Neil Yeager
    Are your ants metric or imperial there?
  • JR Knifemaker
    metric. Sensible metric ants.
  • Bryn Davies
    "the width of an ant"! I fucking love it! All metric to imperial conversions should henceforth be translated into invertebrate comparisons.
  • JR Knifemaker
    we can all identify with an ant’s width.
    We can then upscale and downscale
    Bees. Woodlice. House spiders. Much more international standards of measurement.
    Unless you live in Australia.
  • JH Forgeworks
    Anything under 1/8th inch I'll just break the 90's and do my grinding post heat-treat. The exception being smaller edc type blades with less than a 3.5 inch cutting edge. Those usually carry a thicker unground spine so warping is less of an issue. I won't take them to final thickness but will do about 60-75% of the grinding pre-heat treat.

    I find that, even with carbon blades, I'll use a pair of 1.5 inch aluminum plates in a woodworkers vise. For carbon steels I'll quench in Parks then transfer to the plates. This has considerably minimized my warping issues even on loner 8+ inch chefs blades. I actually just did a 1/16th inch 8.5 inch fillet knife and managed to bring it out of the quench dead flat using this method. Ground everything afterward.
  • JR Knifemaker
    this is a great idea with plates post quench. I’ll give that a go!
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